Examine source code of nos2x

{
  "name": "nos2x",
  "description": "Nostr Signer Extension",
  "version": "1.4.0",
  "homepage_url": "https://github.com/fiatjaf/nos2x",
  "manifest_version": 2,
  "icons": {
    "16": "icons/16x16.png",
    "32": "icons/32x32.png",
    "48": "icons/48x48.png",
    "128": "icons/128x128.png"
  },
  "background": {
    "scripts": [
      "background.build.js"
    ]
  },
  "browser_action": {
    "default_title": "nos2x",
    "default_popup": "popup.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content-script.build.js"
      ]
    }
  ],
  "permissions": [
    "storage"
  ],
  "web_accessible_resources": [
    "nostr-provider.js"
  ],
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self';",
  "browser_specific_settings": {
    "gecko": {
      "id": "{3a9e4477-2d8a-46ea-b507-3ddc2fd07bf1}"
    }
  }
}